Waterways are commonly formed and cleaned by dredges using suction heads connected to large-capacity high-pressure pumps which draw the waterway spoils into the pump for discharging through pipes at a remote onshore location. The cutting and dredging action of the suction heads is often improved by utilizing rotating cutters within the cutterhead front face, as shown in my U.S. Pat. No. 3,971,148.
While submerged cutterheads are effective to remove spoils and material below the water level, such apparatus encounters difficulty in effectively handling material which extends above the cutterhead front face, particularly when such material comprises "upland" spoils extending above the water surface, as commonly found in swamps and other wetlands. A dredge suction head requires large amounts of water to function and while the submerged cutterhead may extend below upland material, this material often does not crumble and fall into the cutterhead due to vegetation and root structure tending to maintain the integrity of the soil.
It is an object of the invention to provide an attachment for a dredge suction head which permits the suction head to effectively dredge upland material located above the suction head, and even above the water line.
An additional object of the invention is to provide a dredge cutterhead attachment for handling upland material which simultaneously breaks up and pulverizes the upland spoils while conveying the same toward the suction head.
A further object of the invention is to provide a cutterhead attachment for handling upland material wherein the vertical position of the attachment may be readily adjusted in a vertical direction.
In the practice of the invention a bracket is pivotally mounted to the upper portion of a dredge cutterhead at its inner end, and a shaft is rotatably mounted upon the bracket at the outer region thereof. The shaft axis is horizontally disposed and is located forward and above the dredge housing front face substantially parallel thereto. A plurality of radially extending hoe-like fingers are mounted upon the shaft and spade elements are attached to the outer ends of the fingers substantially tangential to the direction of finger movement. A hydraulic rotary motor is attached to the shaft for rotating the shaft and fingers, and an expansible chamber motor is employed to adjust the vertical orientation of the bracket relative to the cutterhead.
The shaft and fingers are rotated in a direction wherein the spades and fingers are brought downwardly into engagement with the upland material for pulverizing and breaking up the same, and as the shaft precedes the suction head front face, the direction of finger movement will move the pulverized upland material toward the dredge front face where it may be further broken up and fed into the head section line for removal. Vertical adjustment of the shaft and fingers by the expansible chamber motor permits the most effective operation of the upland attachment for the particular depth at which the dredge cutterhead is operating.